Abstract: A cable (20) which may be used in an aerial or buried installation to serve customers' premises and which is a composite optical fiber-copper conductor type serves present customer needs but has the capability to fulfill the service requirements predicted in the communications market of tomorrow. The cable includes one or more reinforced optical fiber units (22--22) and one or more metallic conductor pairs enclosed in a sheath system. Each optical fiber unit is reinforced to include a plurality of strength members (40--40) arrayed about a buffered optical fiber (36) to enclose the optical fiber and to provide columnar strength to resist compressive forces. A filling compound (52) is disposed within the unit between a jacket (50) which encloses the strength members and the buffered optical fiber.

Abstract: Arrangement and method for avoiding the processing time associated with executing branch instructions in a computer. An instruction fetch unit appends a next instruction address field to each instruction it passes it via an instruction cache to an instruction execution unit. The fetch unit decodes the present instruction being read and the next sequential instruction in main memory. If neither instruction is a branch instruction, the next address field is set to the address of the next sequential instruction. If the present instruction is a branch, the next instruction address field is set to the branch address contained in the present instruction. If neither of these cases are true and the next sequential instruction from main memory is a branch, the next instruction address field is set to the branch address of this instruction. The execution unit uses the next instruction address to access instructions from the instruction cache. Thus, execution of branch instructions by the execution unit are avoided.

Abstract: An improved technique for blowing conductive links with a laser provides for a wider range of acceptable laser energies. The link in an upper interconnect level is placed on a pedestal, typically formed by etching away a thin layer of the underlying dielectric on which the conductive link is formed. A link in a lower interconnect level thereby has the thickness of the dielectric overlying it reduced. This has been found to reduce the minimum laser energy required to cleanly blow the links in both levels and to reduce the effect of link orientation on the required laser energy.

Abstract: Maximum frequency range in a CMOS voltage-controllable crystal oscillator is obtained with a two-stage amplifier with feedback across both stages. The first stage is connected in source-follower configuration to minimize input capacitance, and the second stage provides the needed gain. To eliminate body effect, the source electrode and body of the second stage CMOS device are connected together. A bidirectional voltage limiter connected to a crystal node limits the oscillations to a symmetrical waveform. Changes in effective duty cycle caused by the different triggering levels of diverse logic connected to the oscillator output are compensated for by selectively shifting dc bias to a buffer amplifier.

Abstract: A semiconductor integrated resonant-tunneling device having multiple negative-resistance regions, and having essentially equal current peaks in such regions, is useful as a highly compact element, e.g., in apparatus designed for ternary logic operations, frequency multiplication, waveform scrambling, memory operation, parity-bit generation, and coaxial-line driving. The device can be made by layer deposition on a substrate and includes a resonant-tunneling structure between contacts such that side-by-side first and third contacts are on one side, and a second contact is on the opposite side of the resonant-tunneling structure. Disclosed further are (two-terminal) resonant-tunneling diodes as incorporated in memory devices, e.g., in lieu of 2-transistsor flip-flops; room-temperature device operation; and devices comprising an essentially undoped accelerator region between an emitter contact and a resonant-tunneling structure.

Abstract: There is disclosed a message formatting arrangement which allows messages from a central processor to be distributed over a bus to a plurality of remote processors using a single address presentation for any message without regard to the byte length of the message. Each message consists of a variable number of sub-messages each having a 3-bit qualifier which specifies the sub-message type. Each remote processor is capable of determining the length of each sub-message depending jointly upon the value of the qualifier and upon the context byte which precedes each group of sub-messages. The remote processors having the capability of skipping over a variable number of idle frames without beginning to process a new message.

Abstract: Highly frequency-selective reflectivity is realized in an optical device including a waveguide and an evanescent-field coupled grating resonator cavity. The device may include a light source and serve as a low-chirp, narrow-linewidth communications laser for use, e.g., for transmission over a fiber having non-negligible dispersion and also in wavelength-multiplexed coherent systems.

Abstract: In an optical fiber connector (20), an alignment sleeve (66) for holding two conically shaped portions (30-30) of plug (24-24) of plug assemblies (22-22) each of which terminates an optical fiber (25) of a cable (35) includes two conically shaped cavities (68,70) communicating through a common plane (72). The conically shaped portion of each plug is urged toward the center of the sleeve by a spring (44). Each plug assembly at its cable entrance end is provided with an end retainer (80) having a central opening which is larger than the cross sectional area of the plug body but not of a retaining ring (42) disposed around the plug. When caps (46-46) of the plug assemblies are mounted and turned into a coupling housing (57) which encloses the sleeve and which is supported by a panel, the sleeve is maintained in a floating position under the urging of each plug. The sleeve together with the plugs therein is capable of movement prior to the occurrence of relative movement between one of the plugs and the sleeve.

Abstract: A single mode optical fiber is disclosed. The refractive index profile of the fiber comprises a depressed-index or trench region in the cladding region. By suitable adjustment of the position, width and index of the trench region, one or more fiber characteristics can be improved, relative to a similar fiber that does not comprise an index trench.

Abstract: Low defect density oxides suitable for use as thin gate oxides or in charge storage capacitors are described. First and second layers are formed on a substrate with misaligned defect structures. A third layer is then grown by diffusing a species through the first and second layers to the substrate. The species reacts with the substrate. The low defect density results from the misaligned defect structure of the first and second layers. In one embodiment, the first and second layers are grown and deposited oxides, respectively. The third layer is grown by diffusing oxygen through the first two layers and the interface between the first and second layers acts as a sink trapping defects. The oxide silicon interface has desirable characteristics because the oxide grows in near equilibrium conditions.

Abstract: Metallization of integrated devices using ruthenium as a metallization material results in well-adhering contacts to source and drain regions as well as to gate oxide. Ruthenium is similarly suited as a diffusion barrier metallization between, e.g., silicon and aluminum and as an interconnection metallization material. And, as a diffusion barrier material, ruthenium dioxide may be used.

Abstract: A universal protocol data receiver is disclosed which is capable of receiving data streams in character mode and block mode, providing flow control and error detection and correction. The receiver is divided into two stages separated by a first-in, first-out buffer register. The first stage handles flow control and error processing as well as initialization. The second stage handles interfacing with the data utilizing mechanism and flow control acknowledgements. The FIFO buffer is divided into two parts by a movable barrier which limits the access of the second stage. The barrier permits error processing by hiding incoming blocks of data behind the barrier until processing is complete. Both a hardware and a software implementation of the receiver are disclosed.

Abstract: An optical fiber (21) which has been drawn from a preform (22) is moved into and through a chamber (38) of a housing. A source of vacuum is connected to the chamber to prevent the attachment of air pockets to the optical fiber as it is being moved through the chamber and through an opening of a die. The die includes a flow path (55) which is substantially normal to the path of travel of the optical fiber and the die opening is substantially larger than the diameter of the optical fiber. The thickness of the flow path in a direction along the path of travel is sufficiently small so as to prevent the recirculation of the coating material in the vicinity of the point of application to the optical fiber. Also, the fiber draw rate, the pressure of the coating material the direction of the flow path relative to the longitudinal axis of the optical fiber and the diameter of the die opening are such that a gap forms between the coating material and the die.

Abstract: The optical fiber connector comprises two right circular drawn glass capillary cylinders, means for maintaining the cylinders in substantially fixed relative radial relation, and means for maintaining the cylinders in substantially fixed relative axial relation. The invention has a multiplicity of embodiments, including connectors functioning as variable attenuators, as fiber-to-fiber switches and connectors comprising an in-line filtering element. Connectors according to the invention can have very low insertion loss, are easily field-installed, can be easily and inexpensively manufactured, and are useful for single mode as well as for multimode fiber applications.

Abstract: A speech recognition system and technique of the acoustic/phonetic type is made speaker-independent and capable of continuous speech recognition during fluent discourse by a combination of techniques which include, inter alia, using a so-called continuously-variable-duration hidden Markov vodel in identifying word segments, i.e., phonetic units, and developing proposed phonetic sequences by a durationally-responsive recursion before any lexical access is attempted. Lexical access is facilitated by the phonetic transcriptions provided by the durationally-responsive recursion; and the resulting array of word candidates facilitates the subsequent alignment of the word candidates with the acoustic feature signals. A separate step is used for aligning the members of the candidate word arrays with the acoustic feature signals representative of the corresponding portion of the utterance.

Abstract: A frequency-hopping radio communication system is disclosed comprising a control unit which transmits to and receives from each of a plurality of slave stations using a frequency-hopping mode of operation. During a start-up mode, the control unit communicates a starting message to each slave station using a predefined frequency. The message identifies to each slave station a frequency-hopping sequence to be used to select the frequencies from a group of frequencies for transmission to and reception from the control unit. This message also specifies to each slave station unique starting frequencies in the frequency-hopping sequence at which to begin transmitting and receiving. All slave station transmissions are synchronized to the control unit transmissions, thereby preventing any two stations from concurrently using the same frequencies for either transmitting to or receiving from the control unit.

Abstract: An improved CMOS bandgap voltage reference in which a magnified current derived from a thermal voltage reference produces a voltage drop across a resistor. The resistor in turn couples to a single bipolar transistor which is part of the thermal voltage reference. The bandgap voltage is the sum of the voltage across the resistor and the voltage across the bipolar transistor. In addition, the immunity of a bandgap voltage reference to variations in power supply variations is improved by having a differential amplifier sense the voltages at the control current input and the output of a current mirror in the thermal voltage reference portion of the bandgap voltage reference and adjusting the power supply voltage to the thermal voltage reference until the sensed voltages are substantially the same.

Abstract: There is disclosed a system for providing an economical telephone toll service in which a telephone subscriber selects the economical service by, for example, sending an appropriate signal, and then dials his directory assistance call or other telephone toll call. After the caller's options are determined and typically before signaling for the call is commenced, a recorded-announcement of an aural or visual nature is connected to the subscriber's line, the announcement consisting of at least one advertisement. The advertisements are selected from a databank according to some predetermined technique of selection, which may include any number of factors or features to make the service attractive to subscribers and of a nature to make the service also sufficiently rewarding to advertisers.

Abstract: Methods of and apparatus for winding strand such as optical fibers on altate spools and for storing and protecting from damage coiled end portions of the strand to be wound on the spools in which the coils are clamped laterally of the coils with forces applied parallel to the axis of the coils. The methods and apparatus of the invention may be used for urging portions of the strand being fed to the spools and associated strand storage and clamping devices against the peripheral surfaces thereof to aid in the transfer of the distribution of the strand from one spool to the other spool.